Polly was the secretary of Professor Brett, the
inventor of WOTAN, the computer responsible for building the War
Machines, which would have taken over the world without The First
Doctor's intervention. The outgoing Polly quickly befriended Dodo
Chaplet, and was able to cheer up seaman Ben Jackson, who repaid the
favor by rescuing her from WOTAN. Polly and Ben's journeys in the
TARDIS were accidental, as they entered the ship to return Dodo's
key just as The Doctor prepared for takeoff (The War
Machines). After an adventure in 17th century Cornwall, she and
Ben were with The Doctor when the Cybermen attempted to take over
Earth, and were the first companions to witness the miracle of
regeneration (The Tenth Planet). They remained with The
Doctor during the early part of his second incarnation, and Polly,
though often frightened, and frequently being relegated to making
the tea, enjoyed her time with The Doctor, and became especially
fond of Ben. The two of them left The Doctor when they found that
their travels had brought them full circle, back to the very day
they stumbled into the TARDIS (The Faceless Ones).

Ben was a sailor without a ship, assigned to a
temporary shore posting when he first met Polly and Dodo in the
Inferno nightclub. He responded quickly to Polly's efforts to bring
him out of his shell, and found himself involved with The First
Doctor's struggle against WOTAN. Ben often questioned things he
didn't understand, most notably The Doctor's regeneration. He was
fond of Polly, though he considered her a bit posh, and quickly
tagged her with the nickname "Duchess". He was protective of her,
and of The Doctor, initially because of the old man's frailty, and
after his regeneration, because of his scatterbrained approach to
the problems they faced. Though he enjoyed his travels, Ben was glad
to return to his own time, and to the relative peace and quiet of
the life of an ordinary seaman.

James Robert McCrimmon was a young Scottish piper
caught in the aftermath of the battle of Culloden when he met The
Doctor, Polly and Ben. After helping them free his friends from the
clutches of the English, he stayed with them to guide them back to
the TARDIS. The Doctor, perhaps fearing for Jamie's safety, invited
him aboard (The Highlanders), and Jamie soon became a
seasoned adventurer. Although confused a bit by technology, he
adapted quickly and seemed to suffer few effects of what is often
described as "culture shock". Jamie was The Doctor's longest-serving
companion, remaining with him until the end of his second
incarnation. While fond of Ben and Polly, he seemed more comfortable
with Victoria Waterfield, whose own time was not so far removed from
his, and Zoe Herriot, a tiny girl whom he felt quite protective of.
Jamie and The Doctor had a relationship marked by good-natured
teasing, although their association sometimes had its dark side, as
when the young man threatened to leave when The Doctor was
apparently helping the Daleks in their latest plan (The Evil of
the Daleks). Jamie accompanied The Doctor on several missions
for the Time Lords, encountering The Sixth Doctor and his companion
Peri Brown (The Two Doctors), and battling the Cybermen on
Planet 14 (The Invasion). The Time Lords erased his memory of
these events, and did so again after The Doctor was brought to
Gallifrey to stand trial for his interference. Jamie was allowed to
remember his first adventure with The Doctor, and was returned to
his own time, where he almost immediately became involved in a fight
against an English soldier (The War Games). His final fate is unknown.

Victoria was the daughter of Edward
Waterfield, whose time travel experiments brought him to the
attention of the Daleks, and led to his death (The Evil of the
Daleks). The Doctor had promised that he'd look after Victoria,
and while he and Jamie did their best to protect her, it's safe to
say that Victoria wasn't cut out for a life of adventure. She was
frequently scared out of her wits by the likes of the Cybermen,
Yeti, and Ice Warriors, and took a break to study graphology (The
Two Doctors). It seems likely that she decided during this
period that she wanted to settle down in a safe place. Following
their next adventure, in which The Doctor defeated the menace by
using the sound of Victoria's amplified screams as a weapon, she
chose to stay behind, much to the sorrow of The Doctor and Jamie (Fury from the Deep).

Zoe was the parapsychology librarian of a space
station, who helped The Doctor and Jamie in a battle against the
Cybermen, and then stowed away in the TARDIS (The Wheel in
Space). She was qualified in many scientific fields, as the
result of a photographic memory coupled with the advanced learning
techniques of her era, and often teased The Doctor by comparing
their intelligence scores. She had little practical experience,
however, and learned a great deal during her time with The Doctor.
Sadly, however, most of this knowledge was lost when the Time Lords
erased her memory of all but her first adventure with The Doctor
before they returned her to her own time (The War Games).